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JY Company: Fixed ROM nametable logic

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This commit is contained in:
Sour 2018-06-16 23:41:23 -04:00
parent dc48591397
commit d568b63cd9
1 changed files with 19 additions and 6 deletions
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23
Core/JyCompany.h
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@ -233,13 +233,8 @@ protected:
//"Mapper 211 behaves as though N were always set (1), and mapper 090 behaves as though N were always clear(0)."
if((_advancedNtControl || _mapperID == 211) && _mapperID != 90) {
for(int i = 0; i < 4; i++) {
if(_disableNtRam || (_ntLowRegs[i] & 0x80) != (_ntRamSelectBit & 0x80)) {
SetPpuMemoryMapping(0x2000 + 0x400 * i, 0x23FF + 0x400 * i, _ntLowRegs[i] | (_ntHighRegs[i] << 8), ChrMemoryType::ChrRom);
SetPpuMemoryMapping(0x3000 + 0x400 * i, 0x33FF + 0x400 * i, _ntLowRegs[i] | (_ntHighRegs[i] << 8), ChrMemoryType::ChrRom);
} else {
SetNametable(i, _ntLowRegs[i] & 0x01);
}
}
} else {
switch(_mirroringReg) {
case 0: SetMirroringType(MirroringType::Vertical); break;
@ -357,6 +352,24 @@ protected:
if(_irqSource == JyIrqSource::PpuRead && type == MemoryOperationType::PpuRenderingRead) {
TickIrqCounter();
}
if(addr >= 0x2000) {
//This behavior only affects reads, not writes.
//Additional info: https://forums.nesdev.com/viewtopic.php?f=3&t=17198
if((_advancedNtControl || _mapperID == 211) && _mapperID != 90) {
uint8_t ntIndex = ((addr & 0x2FFF) - 0x2000) / 0x400;
if(_disableNtRam || (_ntLowRegs[ntIndex] & 0x80) != (_ntRamSelectBit & 0x80)) {
uint16_t chrPage = _ntLowRegs[ntIndex] | (_ntHighRegs[ntIndex] << 8);
uint32_t chrOffset = chrPage * 0x400 + (addr & 0x3FF);
if(_chrRomSize > chrOffset) {
return _chrRom[chrOffset];
} else {
return 0;
}
}
}
}
return BaseMapper::MapperReadVRAM(addr, type);
}